"This kid is the best and he is 14 today," she wrote in the caption. "Unbelievable. He is the kindest little man and he has the most unique way of looking at the world and expressing himself. Mosey, I could not be more proud of you in every way. You conquer all you set out to do, you never quit, you are immensely talented and a great friend. I hope you never stop hugging me goodbye when you go into the next room. I love you."

The pictures feature a close-up of the teenager, one in which he's skateboarding, and one in which he's taken the microphone (and we're pretty sure that's Martin off to the side on piano).